STRUCTURES OF SCOLYTID^E. 



581 



Hopkins' classification the mass of information contained in the 

 works mentioned, incorporating some data obtained from Mr. 

 H. W. Wenzel, of Philadelphia, who has collected many species 

 in winter and early spring by searching for the clusters of wood 

 dust that mark the entrance burrows. 



D 



Fig. 136. Antennae of genera of Scolytidre. A, Antenna of Micracis; 

 B, of Platypus; C, of Scolytus; D, _of Pli/a-osinns. (After Hopkins and 



Swaine.) 



The variations in the club and funicle of antennae are so im- 

 portant as to have become the basis in a large part of LeConte's 



A 



D 



Fig. 137. Antennae of genera of Scolytidas. A, Antenna of Pityogenes; B, of Mon- 

 arthrum; C, of Pityophthorus; D, of Hylastiinis; E, of Xylocleptes; F, of Chra- 

 mesus; G, of Hylnrgops; H, of Dcndrocionus ; I, of Phlceotribus. (After Swaine.) 



